# Questions tagged [speed-of-light]

The speed of light is a fundamental universal constant that marks the maximum speed at which energy and information can propagate. Its value is $299792458\frac{\mathrm{m}}{\mathrm{s}}$.

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### Surpassing 70%c of spinning black holes - projection [closed]

And in some cases, the holes are spinning at an extremely rapid pace. The hole in one quasar, Einstein Cross, was spinning about as fast as theoretically possible -- 70 percent the speed of light In ...
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### Do objects outside the Hubble sphere violate special relativity?

According to special relativity, objects can move with speed at most c. However, objects outside the Hubble sphere recede from us faster than the speed of light. How can these be reconciled?
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### Is Feynman right? Does mass change with speed? [duplicate]

In chapter one of Feynman's famous Lectures on Physics, he writes the following. Mass is found to increase with velocity, but appreciable increases require velocities near that of light. A true law ...
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### If a proton travels exactly at 99% of speed of light are the individual velocities of the quarks inside it also exactly 99% of $c$?

If a proton travels exactly at 99% of speed of light are the individual velocities of the quarks inside it also exactly 99% of $c$? So can we think that they all travel linearly as the center of mass ...
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### Measuring the speed of light with a black hole

is it possible to use the grabity a black hole has to bend the light back to the observer and measure it that way? also saying i made the light go from the right and bend back coming at my left and ...
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### Relativistic ship and base on Earth talking

Let say humans make it possible to travel so close to the speed of light that time dilation for the ship can achieve 100 times the time of a standing still object. So one of that ships starts its ...
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### Why should the speed of light necessarily be the same for all observers in train thought experiment?

I am learning about train thought experiment that explains relativity of simultaneity , but this picture confuses my mind. It seems to me even if the speed of light is not the same for all observers,...
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### Why does the universality of the speed of light prove there is no ether?

So I definitely don’t think there is an ether for starters. I am reading electrodynamics by Griffith and he states that Einstein’s second postulate which says “The speed of light in vacuum is the same ...
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### Special relativity time dilation [duplicate]

According to special relativity time should stop for a particle moving at the speed of light, doesn't that mean that the particle stops moving as well? Then it is not going at the speed of light ...
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### Bluetooth Latency

Considering Bluetooth uses EMR, and EMR requires x amount of time to travel any distance. Does this mean the farther my Bluetooth headphones get from my phone, the gaps between each byte of music ...
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